Concept
required- EEG or Electro Encephalo Gram is a test which is
used to find out about the bio potential of the brain.
Solution
-
The block diagram of EEG is shown as below -
Now let's see the explanation of this block diagram -
- Montage selector- This selects a channel out
of many that convey different info. The 10-20 electrode is
symmetrically placed due to the fact that Montages are also.
symmetrical. The montage selector consists many switches of which
the user can select any.
- Pre-Amplifier - They amplifies the low
amplitude level ( of micro-volt range ) into some range which can
be worked with easily in processing stage. High gain , High CMRR
operational amplifier is generally used for this purpose
- Filters and amplifiers - The noise from the
muscle artifacts make reading untrustworthy. So the filters removes
this noise and amplifies them to improve the amplitude of EEG
waveform.
- Writing recorder and paper drive -
The main task of writing is done by ink type writing recorder,
where the recorder is a chart paper. A stable paper drive mechanism
gives for an accurate EEG waveform
- Analog and Digital Converters (ADC) - They
convert analog EEG signals into the digital signals which can be
used by the computers as the computers can only understand digital
signals
- Oscilloscope - It is generally used to see the
EEG waveform in a digital format. This can be stored and saved for
future reference.
Now let's see the frequency range of the EEG.
- Gamma - It has frequency in the range of 30 -
100 HZ
- Beta - It has range 12- 30 Hz
- Alpha - It has range 8-12 Hz
- Theta - It has range 4-7 Hz
- Delta - It has range 0-4 Hz
And that's how we get the answer :0